English: Map of the Cornubian batholith and the Haig Fras granite, outcrops taken from various published maps and 20 mGal Bouguer gravity contour taken from Edwards 1984 [1] and Taylor 2007 [2] - base is a snapshot from NASA World Wind software. The granite intrusions are lower in density than the average for the upper part of the continental crust and therefore show up as a negative anomaly where the observed gravitational field has been corrected for the effects of topography (the Bouguer correction). The 20 mGal contour is there to show the extent of this negative anomaly.